St John's wort

{| border="1" cellspacing="0" align="right" cellpadding="2"\n! align="center" bgcolor=lightgreen | St. John's wort\n|-\n|! align="center" |\n|-\n! align="center" bgcolor=lightgreen | Scientific classification\n|-\n|\n{| align="center"\n| align=left | Kingdom: || Plantae\n|-\n|| Division: || Magnoliophyta\n|-\n|| Class: || Magnoliopsida\n|- \n|| Order: || Theales \n|- \n|| Family: || Clusiaceae\n|-\n|| Genus: || Hypericum\n|-\n|| Species: || perforatum\n|}\n|-\n! align="center" bgcolor="lightgreen" | Binomial name\n|-\n! align="left" | Hypericum perforatum L\n|-\n|} St John's wort used alone refers to the species Hypericum perforatum, also known as Klamath weed or Goat weed, but is used with qualifiers to refer to any species of the genus Hypericum. H. perforatum is sometimes called Common St. John's wort to distinguish it. The species of Hypericum have been placed by some in the family Hypericaceae, but more recently have been included in the Clusiaceae Hypericum perforatum is a yellow-flowering, rhizomatous, perennial herb indigenous to Europe, which has been introduced to the Americas and grows wild in many meadows. The name comes from the fact that it traditionally flowers by and is harvested on St John's day; all above-ground parts are cut and dried for later use in the form of herbal tea, which has long been enjoyed both for its pleasant (though somewhat bitter) taste and for its medicinal properties. The name perforatum refers to the small windows in the leaves, which can be seen when they are held against the light. In modern medicine, standardized Hypericum extract (obtained from H. perforatum) is commonly used as a treatment for depression and anxiety disorders. In homeopathy, Hypericum is used in the treatment of numerous medical problems, yet the rate of success has not been adequately documented.\nHistorically, the flowers and stems of St John's wort have also been used to produce red and yellow dye. Although Hypericum perforatum is grown commercially in some regions, it is listed as a noxious weed in over twenty countries. Ingestion by livestock can cause photosensitization, central nervous system depression, spontaneous abortion, and can lead to death. Effective herbicides for control of Hypericum include 2,4-D, picloram, and glyphosate. In western North America three beetles Chrysolina quadrigemina, Chrysolina hyperici and Agrilus hyperici have been introduced as biocontrol agents.

Medicinal properties

The first recorded use of Hypericum for medicinal purposes dates back to ancient Greece, and it has been used ever since. The herb was also used by Native Americans internally as an abortifacient and externally as an anti-inflammatory, astringent, and antiseptic. In some countries such as Germany, Hypericum is prescribed for mild depression, far more commonly than conventional antidepressant medication.\nStandardized extracts can be bought today as an over-the-counter remedy, usually in pill or capsule form. It is also widely sold in teabags. Many clinical studies have found it to be effective in the treatment of mild to moderate depression, with fewer side effects than many conventional antidepressant medications. It has been found to be of no noticeable effect in the treatment of more serious forms of depression, however. Although the exact mechanism by which it works is unclear, it is believed to involve slowing the disposal of serotonin, thus boosting serotonin levels. Common side effects are extraordinarily vivid dreams (especially if taken just before bedtime), somewhat increased appetite, and a heightened production of urine by the kidneys, thus requiring the patient to increase fluid intake to avoid dehydration. The usual dosage is 900 mg of Hypericum extract per day, usually made up of three 300 mg capsules or tablets taken at different times of the day. The dosage might need to be varied according to the patient's body weight. Advocates recommend that, as with other antidepressants, Hypericum be taken for at least four weeks before judging its effectiveness. In markets where standardized extracts are not available, the potency of samples can vary widely. Some brands of over-the-counter St. John's wort can be much more potent than others. The same can even be true of two dosage units from different batches of the same brand. Casual use of Hypericum extracts in patients on other medication is not recommended as it can cause sometimes serious drug interactions, including preventing other antidepressants from functioning. It also is known to cause photosensitivity, i.e. increased sensitivity to light, which can lead to sunburns in situations that would not normally cause them.

External links

\n* See http://www.cc.nih.gov/ccc/aboutcc/media_resources/news_features/wortfinal.html for an example of drug interactions with St. John's wort\n*St John's wort information website Category:Medicinal plants \n\n\n\n